Revert "net: stmmac: correct MAC propagation delay"

This reverts commit 20bf98c9.

Richard raised concerns about correctness of the code on previous
generations of the HW.

Fixes: 20bf98c9 ("net: stmmac: correct MAC propagation delay")
Link: https://lore.kernel.org/all/ZMGIuKVP7BEotbrn@hoboy.vegasvil.org/
Link: https://lore.kernel.org/r/20230726224054.3241127-1-kuba@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>